Human papillomavirus (HPV) infections are associated with acute and recurrent disease in sexually active individuals and with squamous cell carcinomas in the female and male genital tracts. In addition, the viruses may be transmitted from an infected mother to her offspring at (or before) birth and cause respiratory papillomatosis in the child. The proposed investigations will determine the outcome of initially asymptomatic HPV infections, assess virus prevalence and virus activation during pregnancy, examine virologically the events at birth to understand mother to offspring transmission, evaluate the role of HPVs in the etiology of cervical adenocarcinoma, ovarian tumors and other genital tract pathologies and examine the role of HPVs as risk factors in squamous cell carcinoma of the cervix. Diagnosis of HPV will be made by dot blot, Southern and in situ hybridization assays. In addition, the technique of gene amplication by polymerase chain reaction will be established in the laboratory and utilized as a means of HPV diagnosis. Virus-excreting asymptomatic women attending the Baltimore City STD clinics will be monitored prospectively for virus prevalence, virus type and the development of cytologic and clinical abnormalities. Women attending the Obstetrics Clinic of Johns Hopkins Hospital will be monitored for HPV prevalence during pregnancy beginning with their first visit to the Clinic. At the time of delivery, exfoliated cervical cells from the mother, respiratory secretions of the neonate, placenta, amnion and amniotic fluid will be assayed for presence of HPV. Fresh specimens and pathological material collected at the Johns Hopkins Hospital will be investigated for the presence, localization and the state of the HPV genome. About 3,000 specimens collected in two WHO case-control studies of cervical cancer will be examined for HPV type, amount of virus and frequency of viral integration. The results of these investigations will clarify some aspects of the biology of HPV infections and assist in evaluation of the role of HPvs in the etiology of lower genital tract cancers.